Presser mechanism for sewing machines

ABSTRACT

This disclosure relates to a low inertia adjustable stroke presser foot for sewing machines which is operable to feed the uppermost ply of superimposed plies being sewn to compensate for the drag exerted by the presser foot sole upon the upper ply. The presser foot is automatically driven through its cooperation with the feed dog and effects the feeding of the upper ply at the termination of the work feeding action of the feed dog. The presser foot includes two sole plates mounted for operation in unison while being relatively movable to one another to compensate for a variation in the number of plies between the two sole plates.

United States Patent Godsen an. 12, 1974 PRESSER MECHANISM FOR SEWING2,487,285 11/1949 Voigt 112/235 MACHINES 2,611,333 9/1952 Ritter 112/1512,627,240 2/1953 Johnson et a1 1 12/235 Inventor: Ronald Godsen, g3,623,441 11/1971 Schoij & K10 112/235 73 As' :U' S 1M hi Cm sslgnccgzgz f ac ne 0 pany Primary Examiner-James R. Bolcr AssistantExaminer-Peter Ncrbun 1971 Attorney, Agent, or I 'irm-Charles E. Brown[21] Appl. No.2 202,892

[57} ABSTRACT 52 us. Cl. 112/235 d'sclfmre relates: a low adllfstablc JI t Dosh 29/00 stroke presser foot for sewing machines which is opernable to feed the uppermost ply of Superimposed plies [58] Field ofSearch 112/235, 237, 238, 239,

bemg sewn to compensate for the drag exerted by the 112/240,150, 151,134

presser foot sole upon the upper ply. The presser foot is automaticallydriven through its cooperation with [56] References Cited the feed dogand effects the feeding of the upper ply UNITED STATES PATENTS at thetermination of the work feeding action of the 1,002,330 9/1911 Stedman112/235 feed dog. The presser foot includes two sole plates 1,646,96110/1927 GatChClL-J 1 12/235 mounted for operation in unison while beingrelatively :1 et i movable to one another to compensate for a variation1 1 Ll ner 2,298,770 10/1942 Kuceram 2/235 in the number of pliesbetween the two sole plates. 2,446,852 8/1948 Sailer 112/235 4 Claims, 7Drawing Figures Pmmim 12 am 33196; 113

PRESSER MECHANISM FOR SEWING MACHINES This invention relates in generalto new and useful improvements in sewing machines, and more particularlyto an improved presser foot assembly for sewing machines of the type inwhich a presser foot is disposed on one side of the work and is biasedin opposition to a movable work feeding member disposed on the oppositeside of the work. The invention particularly relates to a presser footassembly of this type wherein different numbers of work plies underliedifferent portions of the presser foot and separate sole plates areprovided for engaging the different plies.

BACKGROUND OF THE INVENTION This invention particularly relates to a lowinertia ad justable stroke presser foot for sewing machines of the typedisclosed in the copending application of Edgar Schoij and Frederick M.Klose entitled PRESSER MECHANISM FOR SEWING MACHINES, Ser. No. 878,635filed Nov. 21, 1969, now U.S. Pat. No. 3,623,441.

The sole plates of the various presser foot arrangements disclosed inthe aforementioned copending application Ser. No. 878,635. is a planarsole plate intended primarily for the sewing of plies which extendentirely beneath the presser foot. However, there are many sewingoperations wherein one portion of the presser foot overlies only one plyof work, for example, and a second portion of the presser foot overliesa multiple number of plies of work. This is particularly true in suchoperations as sewing on pockets, collars, cuffs, etc. The situation alsoexists in such hemming operations as shirt sleeves, blouses, skirts.

In the past, there have been developed compensating presser feet of thetype wherein two sole plates are provided, the sole plates beingrelatively movable with respect to one another whereby one sole platemay engage only a single work ply and the other sole plate will engageone or more work plies which are being stitched to the one work ply.Typical of these compensating presser foot constructions are those foundin the patents to John T. Enos entitled SEWING MACHINE PRESSER-FOOT,U.S. Pat. No. 2,652,016, granted September 15, 1953, and James A. Pisanoentitled CORDING PRESSER-FOOT FOR SEWING MA- CHINES, U.S. Pat. No.2,807,225, granted Sept. 24, 1957. While the individual sole plates ofthese prior presser foot constructions are mounted on common pivotscarried by a bracket, the constructions in no way co-ordinate thepivoting of the two sole plates nor is such co-ordination necessary inthat the bracket is rigidly mounted on the presser bar and there is nochange in the angular relation of the bracket with respect to the planeof the work being stitched.

SUMMARY OF THE INVENTION In accordance with this invention, there isprovided a low inertia adjustable stroke presser foot for sewingmachines which is also of the compensating type and is provided withfirst and second sole plates mounted both for movement in unison and forindividual movement relative to one another.

A principal feature of the invention is the provision of a support armwhich is part of a lever pivotally mounted for cooperating reaction withrespect to a four motion feed assembly whereby a sole plate or solesupport arm with the first and second sole plates having cooperatingmeans whereby the first and second sole plates generally move in unisonwith respect to the support arm and at the same time are relativelymovable with respect to one another, primarily in a vertical direction,to compensate for the varying number of plies underlying the two soleplates.

A feature of the invention is the inter-relationship of the two soleplates whereby the two sole plates react against one another forrelative movement and at the same time are generally movable together asa unit for pivoting about the pivot pin mounting the same.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claims and theseveral views illustrated in the accompanying drawings:

IN THE DRAWINGS FIG. 1 is a partial left end elevational view of alockstitch machine with parts broken away and shown in section, andincorporating the presser mechanism of this invention.

FIG. 2 is a front elevational view of the presser mechanism of FIG. 1together with adjacent portions of the machine.

FIG. 3 is an enlarged rear elevational view of the presser mechanism. 5

FIG. 4 is a vertical sectional view taken along the line 33 FIG. 4 andshows the specific details of the presser mechanism.

FIG. 5 is an enlarged fragmentary vertical sectional view taken alongthe line 55 of FIG. 1.

FIG. 6 is a fragmentary vertical sectional view taken along the line 66of FIG. 4 and shows the relationship of work plies with respect to thesole plates.

FIG. 7 is an exploded perspective view showing the double sole plateconstruction of the presser mechanism.

Referring now to the drawings in detail, it will be seen that there isillustrated in FIG. 1 a base 10 of a lockstitch machine with aconventional feed mechanism, generally identified by the numeral 11,including a feed dog 12. There is also illustrated the customary rotaryhook l3 and throat plate 14, all mounted on the base 10.

Above the base 10 there is illustrated a portion of the conventionalhead 15 which carries in the normal manner a presser bar 16 and a needlebar 17 mounted for vertical reciprocal movement in bushings 18,19,respectively, with a needle 20 being mounted in the lower end of theneedle bar 17. A presser foot, formed in accordance with this inventionand generally identified by the numeral 21, is carried by the lower endof the presser bar 16 and includes a bracket 22 which, as is best shownin FIG. 4, has a bore 23 receiving a reduced diameter portion 24 of thepresser bar 16. The bracket 22 carries suitable set screws 25 (FIG. 2)securing the same on the presser bar 16. I

As is best shown in FIGS. 3 and 4, the bracket 22 has a solid topportion 26 and two downwardly spaced wall portions 27. A stud or pivotpin 28 extends through and between the walls with one end portion 30 ofthe pivot pin 28 being threaded and being threaded into a like threadedbore 31 in one of the wall portions 27. A bellcrank type lever 32 havinga centrally located bushing 33 receiving the pivot pin 28 is mounted forpivotal movement relative to the bracket 22 with an upper portion of thelever 32 being disposed between the walls 27.

With particular reference to FIG. 4, it will be seen that the lever 32includes an upper arm 34 which extends horizontally to the left betweenthe walls 27 and terminates in a bifurcated portion 35. An eyebolt 36has the eye thereof mounted within the bifurcated portion for pivotalmovement by means of a pin 37 carried by the bifurcated portion 35 andextending transversely thereof. The bolt 36 extends upwardly and throughan elongated slot 38 in the solid portion 26 of the bracket 22 andthreadedly engaged on the upper end portion of the bolt 36 is a nut 40having a generally conical shoulder portion 41 depending therefrom.

A spring 42 is contained on the bolt 36 between the nut 40 and the solidportion 26 of the bracket 22 by the nut 40. It will be readily apparentthat when the nut 40 is properly adjusted, the spring 40 will becompressed and the bolt 36 tensioned so as to urge the lever 32 to pivotabout the pivot pin 28 in. a clockwise direction. A stop nut 43 isadjustably-threaded on the bolt 36 and is engageable with the bracket 22to limit pivotal movement of the lever 32 in a counterclockwisedirection. The stop nut 43 is retained in an adjusted position by meansof a lock nut 44.

With particular reference to FIGS. 1 and 5, it will be seen that thebracket 22 has formed in the solid upper portion 26 thereof between theslot 38 and the presser bar 16 a threaded bore 45 opening entirelytherethrough and having adjustably positioned therein a stop screw 46which is engageable with the upper surface of the arm '34 of the lever32. The stop screw 46 limits the pivotal movement of the lever 32 in aclockwise direction. I I

The lever 32 also includes a'second arm 47, which will be describedhereinafter as a support arm. The support arm 47 extends angularlydownwardly and to the right from the pivot pin 28 and terminates in abifurcated portion 48, as is best shown in FIGS. 6 and 7. The bifurcatedportion 48 includes a pair of spaced walls 50,51 having mounted thereintransversely aligned bearings 52,53, respectively. The bifurcatedportion 48 carries a transverse pivot pin 54 which has end portionsthereof seated within the bearings 52, 53 for rotation relative to thebifurcated portion 48.

The pivot pin 54 carries two separately formed and separately actingsole plates generally identified by the numerals 55 and 56.

The sole plate 55 includes a lower work engaging plate member 57 whichhas a mounting block 58 extending upwardly therefrom. The mounting block58 has a transverse bore 60 therethrough of a size to receive the pivotpin 54. The pivot pin 54, in the final assembly of the sole plates55,56, with the bifurcated portion 48, is locked in a center position tothe mounting block 58 by means of a set screw 61. Thus, the sole plate55 is mounted for pivotal movement only with respect to the bifurcatedportion 48, the pivot pin 54 rotating within the bearings 52,53.

It is also to be noted that the upper portion of the mounting block 58is contoured to provide suitable clearance for the upper part of thebifurcated portion 48. Furthermore, the block 58 is offset outwardlyfrom the inner edge of the plate member 57 to define a lower ledge 62.In addition, the upper part of the block 58 projects inwardly over andbeyond the lower ledge 62 to define an overhanging upper ledge 63. Theledges 62 and 63 cooperate with the sole plate 56 in a manner to bedescribed hereinafter.

The sole plate 56 also includes a lower work engaging plate member 64which has a mounting block 65 extending upwardly therefrom. The mountingblock 65 has formed therein a transverse groove 66 of a widthcorresponding to the diameter of the pivot pin 54. Thus, the sole plate56 is mounted for both rocking and vertical sliding movement relative tothe bifurcated portion 48.

On opposite sides of the groove 66, the mounting block 65 is providedwith a pair of bores 67 (FIG. 4) in which are seated lower ends ofsprings 68. It is also to be noted that the lower part of the mountingblock 65 is generally aligned with the inner edge of the plate member 64and that the upper part of the block 65 overhangs inwardly beyond theinner edge of the plate member 64 to define an abutment 70.

When it is desired to assemble the plate members 55,56 with the supportarm 47, the springs 68 are engaged beneath the ledge 63 and thencompressed, after which the sole plates 55,56 are slid together so thatthe inner surfaces of the blocks 58,65 abut one another. At this timedownward movementof the sole plate 56 relative to the sole plate 55 dueto the urging of the springs 68 is limited by engagement of the abutment70 with the lower ledge 62. The sole plates 55,56, so coupled, are thenpositioned between the walls 50, 51 of the bifurcated portion 48 and thepivot pin 54 is passed through the bearing 52, the bore 60, the groove66 and the bearing53. With the pivot pin 54 centered, the set screw 61is tightened to lock the assembly together.

It will be readily apparent that the sole plates 55, 56 are mounted forpivoting in unison about the pivot pin 54 while at the same time thesole plate 56 is movable relative to the sole plate 55 both verticallyand through a limited rocking movement.

Referring to FIG. 4, it will be seen that a spring, generally identifiedby the numeral 71, is carried by the lever 32 and reacts on the rearportion of the plate member 57 urging the same to pivot in acounterclockwise direction (FIG. 4) about the pivot pin 54 and to retaina normal horizontal position. The spring 71 has an upper end portion 72which is secured to the underside of the arm 34 by a screw 73 threadedthereinto. The spring 71 also has a generally S-shaped central portion74 and a lower portion 75 which lower portion 75 engages the platemember 57 and serves to keep the sole plates 55,56 in a selected angularrelation relative to the support arm 47, more particularly in ahorizontal position when the presser mechanism is lifted for insertionor removal of a workpiece.

Referring now to FIG. 6, it will be seen that there is illustrated apractical applicationof the presser foot 22 in applying a shirt pocket76 to a shirt 77. The edge of the shirt pocket has an inwardly directedfold 78. Thus, the sole plate 55 overlies three layers of work while thesole plate 56 overlies only a single layer of work. When the presser bar16 is moved downwardly to apply the presser foot 22 to the work, thesole plate 55 would apply the desired pressure to the three plies ofwork with the support arm 47 being disposed at the desired angle throughthe compression of the spring 42 so as to affect the necessaryadditional feeding of the material of the pocket 76 relative to the basematerial of the shirt 77. At the same, time, the sole plate 56 wouldoffset downwardly relative to the sole plate 55 under the influence ofthe spring 68 and serve as an edge guide for the pocket 76 and also toprevent flagging of the material.

It is to be understood that the amount of pressure applied to thematerial being stitched by the main sole plate 55 will depend upon thecompression of the spring 42 in that this is adjustable by positioningthe nut 40. The amount of pressure applied to the material will dependon the type of finish of the material or the thickness of the material.For example, more pressure would be required for smooth or thin materialthan for rough or thick material in order to obtain a flat, pucker-freeseam.

It is once again pointed out here that without consideration being givento the sole plate 56, the sole plate 55 will function in the mannerdescribed in the aforementioned copending application Ser. No. 878,635while the sole plate 56 will have no feeding function.

Although only a preferred embodiment of the presser foot mechanism hasbeen specifically illustrated and described herein, it is to beunderstood that minor variations may be made in the presser footconstruction without departing from the spirit and scope of theinvention, as defined by the appended claims. I

normal to the general plane of said second sole plate, l

and cooperating means on said first and second sole plates restrictingrelative movement between said first and second sole plates, saidcooperating means including said first sole plate having an upper ledgeoverlying said second sole plate, and resilient means between said.

ledge and second sole plate constantly urging said second sole platetowards a work engaging position.

2. The presser foot assembly of claim 1 wherein said resilient meansinclude springs disposed on opposite sides of said pivot pin.

3. The presser foot assembly of claim 1 together with a lower ledge onsaid first sole plate cooperating with said second sole plate limitingdownward movement of said second sole plate in response to urging ofsaid resilient means.

4. The presser foot assembly of claim 1 wherein said cooperating meansinclude coacting portions of said first and second sole plates inalignment with said pivot pin substantially filling the space withinsaid bifurcated end portion along said pivot pin thereby assuringpositioning of said first and second sole plates axially of said pivotpin. I

1. A presser foot assembly for a sewing machine, said presser footassembly comprising a support arm terminating in a bifurcated endportion, a pivot pin carried by said end portion, a first sole platecarried by said pivot pin for pivotal movement only relative to said endportion, a second sole plate carried by said pivot pin for pivotalmovement and limited movement generally normal to the general plane ofsaid second sole plate, and cooperating means on said first and secondsole plates restricting relative movement between said first and secondsole plates, said cooperating means including said first sole platehaving an upper ledge overlying said second sole plate, and resilientmeans between said ledge and second sole plate constantly urging saidsecond sole plate towards a work engaging position.
 2. The presser footassembly of claim 1 wherein said resilient means include springsdisposed on opposite sides of said pivot pin.
 3. The presser footassembly of claim 1 together with a lower ledge on said first sole platecooperating with said second sole plate limiting downward movement ofsaid second sole plate in response to urging of said resilient means. 4.The presser foot assembly of claim 1 wherein said cooperating meansinclude coacting portions of said first and second sole plates inalignment with said pivot pin substantially filling the space withinsaid bifurcated end portion along said pivot pin thereby assuringpositioning of said first and second sole plates axially of said pivotpin.